Inspecting apparatus



1941- A. c. CHAMBERLIN EEIAL 2,229,633

INSPEGTING APPARATUS Filed Aug 3, 1958 2 Sheets-Sheet 2 Umxq J T W E T,QN @SN atented Jan. 28, 194i IN SPECTIN G APPTUS Alan C. Chamberlin anBethlehem, Pa.,

d Henry W. Nieman,

as'slgnors to Bethlehem Steel Company, a corporation otPesylvaniaApplication August 3, 1938, Serial No. 222,853

16 Claims. (on. 164-68) Our invention relates to the method of anddevices for inspecting material for imperfections and particularly tothe inspection of flat rolled products.

Qne object of our invention is to provide a novel method of inspectingmaterial which will detect imperfections of small dimensionswhich arepervious to light in the material inspected.

Another object of our invention is to provide an inspection device whichwill be-respo'nsive to very small imperfections in'the materialinspected.

A further object of our invention is to provide an inspecting devicewhich will automatically inspect the material and classify it accordingto the characteristics of the material.

A still further object of our invention is to provide a novel method ofoptically inspecting fiat rolled products by disposing said productintermediate an optic and a source of luminous energy which is capableof eifecting said optic.

A still further object of our invention is to provide a device which ishighly sensitive so as to detect holes of very small dimensions inmaterial, especially fiat rolled products which are subsequently to becoated.

A still further object of our'inventio'n is to provide an inspectingdevice which is particularly suitable for inspecting flat'rolledproducts for holes which arepervious to light, and automatical'lydesignating the material having such holes either by sorting saidmaterial from' the remainder of the-material or by indicating'suchdefects, as by marking the material having holes, so

that it can be easily identified.

The novel features of'our invention will be more fully understood fromthe following description and. claims taken with the drawings in which:

Figure 1 is a side view partly in elevation and partly diagrammaticillustrating'one embodiment of our invention; p

Fig. 2 is an enlarged top view of the inspecting device;

Fig. 3 is a section taken on line 33 of Fig. 2; Fig. 4 is a sectiontaken on line 4-4 of Fig.2;

' Fig. 5 is a side view in elevation of a modified structure embodyingour invention; and

Fig. (:7 is av diagrammatic view of the electrical circuits andapparatus embodied in our invention.

Referring to Figs. 1 to 4, inclusive, of the drawings, wherein we haveshown one form of carrying out our invention in connection with'anapparatus which includes a shear, travelling at a high rate of speed forshearing a strip into sheets or the like, it designates slitter rollsthrough which the material It is fed, ii the flying shears for shearingthe material into sheets and which also governs the speed of the striptherethrough, or the like. Located intermediate the slitter rolls l5 andthe shears H is our inspecting device is,

which is especially adaptable for inspecting sheet metal products intheir uncoated condition.

Referring to Fig. 5 we show our invention in connection with a strip ofmaterial which is not sheared-after it passes through the slitter rollsit, but which is recoiled onto the coiler H, which operates to pull thematerial through our 111-- specting device l9.

The inspecting device I9, as clearly shown in Figs. 2 to 4, inclusive,comprises a housing it having openings L2!) and 2! and guides 22 and23,.

through which the strip lS-is guided, these openings and guides beindisposed so that the strip 56 passing therethrough separates the housing89' into upper and lower compartments 2t and 25, respectively. Flaps 26and 2? are provided at the openings 2@ and 2!, respectively, to en. gagethe surfaces of the strip it so as to prevent objectionable light fromentering said compartments. The grooved guides 22 and 23 which areadjustably mounted in the guides 28 and 29, extend beyond the edges ofthe strip l6 and prevent light from entering by the sides of the stripis into the compartment 26. Suitable means are provided for retainingthe guides 22 and 23 in their adjusted positions for variation inthewidth ofthe material to be passed through the housing l9. li/Iounted inthe compartment M is a plurality of light sensitive elements it, whichare preferably photo-electric cells, and which are disposed so as toreceive rays from a source of energy capable of passing throughimperfections in the material it. Lenses 34 are positioned ad- Jacentthe elements it. Mounted in the compartment 25 is a plurality ofilluminating devices 32 for directing luminous energy onto the surfaceof the strip material I6 oppositeto the light sensitive elements 3| sothat any small imperfections in the material l6 pervious to rays fromsaid energy will permit saidrays to pass therethrough into thecompartment 24, through the lenses 3%, and onto the light sensitiveelements 3i.

The. provision of the light sensitive elements 3| so as to'receive rayswhich pass through imperfections in the material being inspectedconstitutes only one phase of the inspection procedure. After thematerial is inspected it is desirable to designatedefectivev materialeither by means which will identify and/or reject defective portions ofthe material being inspected.

Identification may be accomplished by means I device I8 which is clearlyshown in Fig. 1.

The sorting device I8 comprises a deflector or diverting gate 35 whichin its normal position, as shown in full lines in Fig. 1, permits sheetsto pass from the conveyor 39 onto the conveyor 36 and thence to theconveyor 31 and into the receptacle 38 and when the deflector 35 isoperated to the position shown in dotted lines to deflect the sheetsfrom the conveyor 39 into the receptacle 40. The deflector 35 isoperatively connected to suitable control devices hereinafter to bedescribed which are under the control of the light sensitive elements3I.

To provide for the operation of the deflector 35 in timed relation tothe inspecting device I9, regardless of the speed of the material,which, as shown in the drawing, is governed by the speed of the shearI1, a time delay device comprising the generator I24, which controls thespeed of the operation of the deflector or diverting gate 35, isoperatively connected to shear I1, so that a change in the speed of theshear I1 also changes the speed of the operation of the deflector 35upon the light sensitive elements 3I having detected imperfections inthe material IS.

The marking device I4 as shown in Figs. 1 and 5, comprises a solenoidcontrolled marking stylus I45 which is operatively connected to suitablecontrol devices hereinafter to be described which are under the controlof the.light sensitive elements 3|, so that when a defect is detected inthe material passing through the inspecting device the solenoid I36 isimmediately energized and causes the stylus I45 to mark the defectivematerial.

The electrical circuits and controls for the inspecting device I9 andthe sorting device I8 and marking device I4 arelocated in a suitablehousing designated as I0 in Fig. 1. I50, I5I, I52, respectively,designate conduits which contain the electrical wiring to the inspectingdevice I9, the sorting device I8 and the marking device I4,respectively, and I53 a conduit containing the electrical wiring to thegenerator I24. The wiring diagram of the electrical circuits andcontrols being plainly shown in Fig. 6.

Referring to Fig. 6 which shows the arrangement of the electricalparts,.the bank of photocells 3I is connected to microrelay IOI throughamplifier I02, batteries I03, I04 and I05, and resistor I06, as shownfollowing a standard arrangement for such apparatus so that actuatingany of the photocells h, light will cause microrelay IOI to close andremain closed as long as light falls on any of the photocells. Uponclosing microrelay contact I01 an electric circuit is -completed whichpermits current to pass from battery I08 to coils I09 and H0 of relaysIII and H2, causing the armatures H3 and H9 of relays III and ll2,respectively, to move from their out positions, as shown in thedrawings, to their in positions. The movement of armature II3 to its inposition completes a circuit which permits current to flow from batteryI I 4 through .current flows from battery I I4 through actuating coilII5 of time delay relay H6 and holds the armature I21 in its in positionas shown in the drawings and when the armature II3 moves to its inposition the current to the coil I I 5 is interr'upted and permits thearmature I21 to open and to make contact at I28, the time required forsuch operation depending on the current being supplied to the buckingcoil I22. The moving of armature II9 of relay II2 to its in positioncompletes a circuit which permits current to flow from battery II4through coil I20 of time delay relay I2I and causes the armature I3I tocontact at I32 and when the armature H9 is in its out position,'as shownin the drawings, such current will be interrupted to the coil I20.

Time delay relays H6 and. I2I are constructed according to well knownprinciples, each consists,

of an iron core on which is mounted an energizing coil and a buckingcoil. When current passes through the energizing coil a flux isimmediately built up in the iron core pulling the armature into its inposition and holding it in such position for a prolonged period of timeafter the energizing circuit has been opened. This causes a prolongeddelay period in the opening of the armature. To control the length ofthis delay a bucking coil is also placed on the core and a feeblecurrent is applied thereto. The time delay in this case being inverselyproportional to the strength of the bucking current applied.

Bucking coils I22 and I23 of time delay relays H6 and l2l are suppliedwith current from generator I24'through resistances I25 and I26,respectively. The current generated by the generator is proportional toits speed, the time delay of the relays will be inversely proportionalto the speed of the generator, for given settings of resistors I25 andI25. By changing the values of the resistors the timedelay for any givengenerator speed can be adjusted. When armature I21 of relay II6 fallsopen contact is made at I21 and current allowed to pass from battery II4through coil I29 of solenoid I30. When armature I3I of time delay relayI2I is in its in position contact is made at I32. When coil I29 ofsolenoid I30 is energized by the current passing from battery II4, itdraws plunger I34 inwardly. pulling with it arm I35 which is operativelyconnected to diverting gate 35 so that the raising of the arm I35 opensthis gate. I35 is raised, contact is made at I38 so the current can passfrom battery II4 through coil I29 if contact I32 is also closed eventhough contact I28 is open. Arm I35 in moving to its inward positionalso opens switch II8 so as to de-energize coil H1 and release armature3, if this is at that time held in the in position by this coil.

The control. for the marking device I4 comprises a relay I39, having acoil I38 which is in parallel with the coil I20 of relay I2I so thatwhen said coil I20 is energized, as already set forth, coil I38 willalso be energized and armature I40 of relay I39 will be drawn into itsin position and close contact I4I. This will complete the circuitthroughthe battery I42 and permits current to flow from said batterythrough the coil I43 of solenoid I31 and operate plunger I44 with itsmarking stylus I45.

When the arm Switches I46 and lslare placed in the circuits of therejecting and identifying device, respectively, so that either one orboth of the systems may be used at will.

In operation the material it, which is'being inspected, is fed from therolls it through the opening 20 in the inspecting device is intermediatethe grooved guides 22 and 23 and out thrdugh the opening 21 with theflaps 2t and 27 engaging the surfaces of the material it, therebyshutting out the passage of light to the compartment 2d. Theilluminating devices 32 being in operation will direct beams of lightagainst the under surface of the material 56, but due to the structureof the inspecting device is light rays from said illuminating devices 82can not pass to the light sensitiveelements 35 as long as portions ofthe material impervious to rays from said beam are intermediate theilluminating devices 32 and the elements 3i, and the deflector willremain in the position shown in full lines in the drawings and after thematerial has been sheared by the shears it the pieces are passed ontothe conveyors 3t and 3? and into the receptacle 38. If, however, aportion or the material which is passing through the inspecting devicecontains one or more imperfections which are pervious torays from thebeam of light such rays will pass therethrough onto one or more of thelight sensitive elements 38 actuating one or more of the light sensitiveelements or photocells which in turn energizes relays till, ill, and H2and draws the armatures thereof into their in positions. When thearmature N3 of relay Ml is vdrawn into its in position it will remain inthis position after the defect has passed through the inspection deviceand relay Hill is opened because of the action of holding in coil i ll,assuming switch H8 is closed. The drawing of the armature H3 into its inposition will ole-energize the coil N5 of the time delay relay lit andafter a definite period of time, therefore, the arm i271 of time delayrelay H6 falls into its out position closing contact H23 and energizingthe coil 12a of solenoid E38; whereupon plunger 83% of this solenoid isdrawn inward and operates the arm I35, closing the contact led andopening the diverting gate 35. allows arm N3 of relay l i i to go intoits out position and to energize coil 8 it of time delay relay I it,This immediately draws into its in position arm I27, breaking thecontact at i283. The current still continues to flow through solenoidits,- however, since contacts E35 and it? are closed, contact I32 havingbeen closed due to the energizing of the coil Q28 pulling the arm 53Einto contact with this contact 1 32 upon the completion of the circuitthrough this coilby the movement of the arm H9 to its in position for aninstant when the light pervious defect passed through the inspectiondevice. The arm Md immediately returns to its out position as soon asthe defect passes, but the armature 139 is held in contact with thecontact I32 a definite period, which will permit the defective materialto pass by the defiector or diverting gate 35 into the receptacle Q0.After the definite period of time has elapsed the armature lei will dropto its out position and interrupt the current through solenoid 830,which permits arm H335 to move outwardly and close the diverting gate 35and the gate will remain in this position until another defect isdiscovered in the material.

Generator 92 5 is directly connected to the flying shear. so that thecurrent generated by the g to use the inspecting It also opens switchits and generator is proportional to the speed of travel of the materialthrough the flying shear. Re-

sistances I25 andfacs are adjusted so that the diverting gate 35 willnot open until sumcient time has elapsed for the sound materialpreceding the defect to pass the diverting gate 35 and the divertinggate will not close until a slightly longer time interval 'is passed inorder to hold the gate open until suflicient time has elapsed to allowthe defective material to pass through the diverting gate. I

If the marking device is connected, as indicated in the drawings, thatis with the switch is? closed, as the strip being inspected passesthrough the inspecting device and a defect is indicated, the solenoidit)? is ediately ener gized upon the energizing oi the coil its or relayits and the closing of contact ltl which permits current to flow frombattery 6652 through coil its to the solenoid E87. Upon the energizingof solenoid I31 the plunger ltll is drawn inwardly and with itthemarking stylus 965 which is so positioned that it strikes the materialpassing through the inspection device and thus makes a suitable mark onthe material for each defect occurring therein.

When it is desired to use the marking device without the sorting device,the circuit to the sorting device is disconnected by opening the switchlet. The same is true when it is desired device and the marking deviceas shown in Fig. 5 for automatically marking defects in a strip ofmaterial which is recoiled after passing through the inspecting tie-=-vice it.

While we have shown our invention in a plurality of forms, it will beobvious to those skilled in the art that it is not so limited, but issusceptible of various other changes and modifications without departingfrom the spirit thereof, and we-desire, therefore, that only suchtations shall be placed thereupon as are imposed separate said imperfectproducts from the remainder of the products. 4

2. A device for inspecting flat rolled products for 1 surfaceimperfections, sensitive element positioned in the path of a beam oflight and shielded from other sources of light, means for disposing theproduct to be inspected across saidpath so that perfect products willshut off said beam. from therein pervious to rays from said beam, willcomprising a light said light sensitive element and imperfect products,having defects admit said rays to said light sensitive element, I

and designating means for said products operatively connected to saidlight sensitive element and actuated upon said rays being admitted tosaid light sensitive element.

3.. A device for inspecting flat rolled products for small holes thereinpreparatory to coating. said device comprising and a beam of light andshielded from. other sources of light, means for disposing said matealight sensitive element rial intermediate said light sensitive deviceand said beam of light so that perfect material will shut off the beamof light to said light sensitive element and imperfect material havingholes therein will permit rays from the beam to pass through said holesonto the light sensitive device.

4. A device for inspecting defects in a member, said device comprising ahousing, a light sensitive element in said housing, means for directinga beam of light towards said light sensitive element, means fordisposing the member to be inspected intermediate said firstmentioned'means and said light sensitive element whereby a perfectmember will effectivelyshut off light to said light sensitive elementand an imperfect member through which light rays from said beam willpass will admit said rays to said light sensitive element.

5. A device for inspecting a fiat rolled product, comprising means fordirecting a beam of light onto one surface of said product, a lightsensitive element shielded from extraneous light and located withrespect to said means so that said element is shielded from said lightbeam by the product when it is impervious to said beam and so that saidelement will receive rays from said beam upon the passage thereofthrough a defect pervious to light in the product, and designating meansactuatable upon said light sensitive element receiving a ray from saidlight beam.

6. A device for inspecting material for small defects therein, saiddevice comprising a light sensitive element, means for directing a beamof light onto said material when said material is disposed intermediatesaid light sensitive device and said means, so that any defects thereinpervious to light will permit rays from said beam to pass therethroughonto the light sensitive element, a sorting device for said material andcontrol means for said sorting device under the control of said lightsensitive element.

\ 7. In combination with an apparatus including a shear for cutting astrip into sheets, a designating device for designating sheets sosheared having holes therein, a device in advance of said shear forinspecting the strip for holes therein, and means controllable by saidinspecting device operatively connected to said designating device.

8. In combination with an apparatus including a shear for cutting astrip into sheets, a sorting device for separating sheets so shearedhaving holes therein, a device in advance of said shear for inspectingthe strip for holes therein, and means controllable by said inspectingdevice operatively connected to said sorting device.

9. In combination with an apparatus including a shear for cutting astrip into sheets, a designating device comprising a marking device anda sorting device for said sheets so sheared having holes therein, adevice for inspecting thestrip or sheets for holes therein, and meanscontrollable by said inspecting device for actuating said marking andsorting devices.

10. In combination with an apparatus including means for feeding a flatrolled metal product, an inspecting device located in the path of saidproduct, said device comprising a light sensitive device shielded fromextraneous light and a source of light for actuating said lightsensitive device, said source of light and said light sensitive devicebeing so arranged that a perfect product interposed therebetween willefiectively shut off rays from said source of light to said lightsensitive device but when imperfections occur in said product which arepervious to said light rays, said imperfections will permit said rays topass therethrough onto said light sensitive device and designating meansfor said imperfections operatively connected to said light sensitivedevice and actuated thereby upon said device receiving rays from saidsource of light.

11. In combination with an apparatus including a shear for cutting astrip into sheets, a sorting device for said sheets, a device in advanceof said sorting device for inspecting the strip for defects therein andmeans operatively connected to the inspecting device for controllingsaid sorting device, said inspecting device comprising means fordirecting a beam of light onto one surface of said strip and a lightsensitive element opposite saidbeam of light and shielded from saidlight by :said strip adapted to receive rays from said beam upon thepassage thereof through a defect insaid strip.

12. An apparatus for inspecting fiat rolled mettalic products or thelike, a housing having grooved guides receptive of the side edges ofsaid products, means for feeding said products through said guides and adevice actuated by light rays positioned in said housing so thatproducts passing through said guides when free from defects willeffectively prevent light rays from reaching said device and when aproduct having defects pervious to light rays passes therethrough lightrays will be directed onto said device.

13. A device for inspecting defects in a member, said device comprisinga housing impervious to light, means for receiving the member to beinspected, a light sensitive element in said housing, an illuminatingdevice adapted to direct rays of light onto the surface of the memberbeing inspected opposite the light sensitive device and onto the lightsensitive device upon a defect pervious to said rays occurring in saidmaterial, said light sensitive element being otherwise shielded from allsources of light.

14. An apparatus comprising an inspecting device, said device comprisinga housing having an entrance thereto for the material to be inspected,grooved guides within said. housing for engaging the side edges of saidmaterial, a source of luminous energy disposed on one side of saidguides and a light sensitive element disposed on the other side of saidguides.

15. An apparatus comprising an inspecting device for fiat rolledproducts and a sorting device for said products, a control for saidsorting device and means operatively connected to said inspecting deviceto render said control effective, said means comprising a relay foroperatively connecting said inspecting device to said control and a timedelay element for said control.

16. An apparatus comprising an inspecting device for inspecting flatrolled products, a shear for cutting said products into smaller units,and a sorting device for said units, a control for said sorting device,and means under the control of the inspecting device for rendering thecontrol efiective, said means comprising means operatively connectingsaid inspecting device to said control and a time delay element for saidmeans operatively connected to said shear.

' ALAN C. CHAMBERLIN.

HENRY W. NIEMAN.

